Quantitative data about security threats is a precondition for a precise assessment of security risks and consequently for an efficient management of information security. Currently such data is hardly available, especially for small and medium-sized organizations. In this paper we discuss different ways of gathering quantitative data and present a new approach for the collection of historical data on security incidents. We propose a platform that collects, aggregates and evaluates data on security incidents from multiple organizations. We identify basic requirements for such a platform and show approaches for satisfying them. We especially emphasize the aspects of security and fairness. Finally we introduce a prototype that shows how an implementation could look like.